FR3147155A1 - Seat upholstery support, comprising an openwork plastic element - Google Patents

Abstract

The present disclosure relates to a seat upholstery support (S), comprising a single-piece plastic element (1) extending from a front cross member (10) to a rear cross member (11) of said plastic element in a longitudinal direction X of the seat and extending from a first longitudinal member (12) to a second longitudinal member (13), in a transverse direction Y of said seat and in which said plastic element (1) comprises a flexible suspension portion (15), extending: - continuously in the longitudinal direction (X) from the intermediate portion (14) to the rear cross member (11) of said plastic element by connecting said intermediate portion (14) to the rear cross member (11), - discontinuously in the transverse direction (Y) between the first longitudinal member (12) and the second longitudinal member (13). Abstract figure: Figure 1

Description

Seat upholstery support, comprising an openwork plastic element

The present disclosure relates to a seat upholstery support comprising a plastic element, intended to support padding, possibly covered by a trim covering (or cover).

The present disclosure also relates to a seat assembly comprising a modular seat cushion and a seat structure having a seat structure comprising two side plates braced by a front crosspiece (or a front tube), transverse, and a rear transverse tube, and in which, said modular seat cushion comprises, in the assembled state, a padding support according to the present disclosure, padding resting on an upper surface of the padding support, or even a trim covering covering the padding.

The present disclosure further relates to a method of obtaining a seat assembly according to the present disclosure.

This disclosure relates to the field of vehicle seats.

The state of the art in vehicle seats involves a seat design that requires the various components of the seat to be assembled at one site, typically using just- in - time manufacturing known as " JIT ".

The seat structure comprises a typically metal seat frame which classically comprises a seat structure and a back structure.

The seat structure may include:
- two slides, right and left, each comprising a lower profile, typically female, fixed relative to a floor, and an upper profile, male, mounted to slide relative to the lower profile, typically in a longitudinal direction which may be the direction of travel of the vehicle,
- a seat structure which conventionally comprises two flanges, right and left, spaced by tubes, and in particular a front spacer or a front tube spaced between the flanges, on a front portion of the seat structure and a rear tube spaced between the flanges on a rear portion of the seat structure, the front and rear tubes extending in parallel, in a transverse direction,
- a metal nose piece forming a front crosspiece which connects the front ends of the flanges and is shaped to form a support surface for supporting the seat cushion.

The height of the seat structure, namely the assembly comprising the flanges and the nose piece, can typically be adjusted by a raising system which can comprise a pair of front links, right and left, connecting the front tube and the upper profiles of the right and left slides, and a pair of rear links, right and left, connecting the rear tube and the upper profiles of the right and left slides.

The seat of such a seat also includes a suspension system typically with spring wires, connecting the nose piece to a rear part of the seat structure, but also a seat padding, typically in expanded polyurethane foam, and a covering covering the foam padding.

Depending on the options that can be chosen by the end user, different comfort equipment can be provided, such as in particular a resistive heating pad, a massage system, or even a ventilation system, or even a sliding mechanism that is fixed above the nose piece so as to be able to adjust the advancement of a front part of the cushion, and relative to a fixed rear portion of the cushion.

A state-of-the-art seat design requires assembling, typically manually, a large number of components at the final vehicle assembly site, which may not be economically optimal when the assembly site has high-cost labor.

Modern seats, especially in higher-end motor vehicles, can be equipped with additional functions, such as heating, massage or ventilation.

These fittings are integrated in the factory during the manufacture of the seat, then topped with the cushions with their padding and coverings. The seat thus assembled is then fixed to the floor of the vehicle.

According to the inventors' findings, and in motor vehicles equipped with such seats, and when the seat is not originally provided with such comfort equipment, the design of the seats known from the state of the art does not allow the seat to be stripped within the vehicle itself, that is to say without removing the seat from the floor of the vehicle, in order to improve the seat by adding an additional heating, ventilation or massage function. Indeed, the addition of such equipment would require removing the seat from the vehicle to remove the coverings and padding, this removal being necessary for such an addition.

However, other seat manufacturing methods are known, for example from document US 9,796,310 B1, which include the pre-assembly, typically on a site separate from the final assembly site of the vehicle, of a module, and in particular a modular seat cushion. This modular cushion comprises, in the assembled state, a base hereinafter called a trim support, padding and a trim covering. It can typically be transported to the final assembly site for assembly on the structure. The trim support comprises a nose piece and a base body;

Notably, the nose piece is articulated to a base body also made of plastic, around a transverse axis of the seat, the nose piece comprising a set of hooks which are fixed to the front tube. According to US 9,796,310 B1 in the event of a frontal impact, the possible rotation between the nose piece and the base contributes to the dissipation of energy during the impact, and favorably supports the hips in order to avoid submarining.

The nose piece is arranged on a front portion of the seat while the base body extends over a rear portion and has a large opening, which receives a metal spring wire suspension.

Also known from document US 4,711,497 is a typically substantially rectangular plastic trim support comprising on the periphery a front cross member, a rear cross member, separated from each other in the longitudinal direction, and side members separated from each other in the transverse direction.

The plastic trim support under a single-piece plastic bucket comprises a wide U-shaped opening, materializing a flexible plate which is adjoining an intermediate portion of the molded plastic body by an edge of the plate, and which comprises an opposite, free edge, juxtaposed to the rear cross member, not linked by molding to the plastic rear cross member, as well as two lateral edges, separated from the side members, not linked to the side members during molding.

The suspension comprises, in addition to said flexible plastic plate configured to pivot around its connection area on the intermediate portion, a torsion spring attached to the rear cross member, connecting the free edge of the plate and the rear cross member, the spring configured to support the free edge of the flexible plate.

According to the inventors' findings, such designs of the trim support according to US 9,796,310 B1 (or according to US 4,711,497) which comprises an assembly of one or more molded plastic parts, on the one hand, and a metal spring system; on the other hand, is expensive and of significant mass.

Also known from document US 8,590,978 B2 is a plastic trim support which comprises a support wall, with slots forming a set of flexible support blades (and in particular 13 flexible blades in ) reducing the rigidity of the plastic support and providing flexibility without requiring the use of a metal suspension.

However, and according to the inventors' findings, each flexible blade of document US 8,590,978 B2 is attached to the plastic body by a single edge and is not very resistant in the event of localized force on the latter, and such as may be encountered if a user presses his knee on the seat.

Generally speaking, and according to the inventors' findings, and in the context of global climate change, there is a need for a padding support, and more generally for a modular seat cushion of a more environmentally friendly design, and in particular one that consumes less material/energy for its manufacture.

Summary

This disclosure improves the situation.

A seat upholstery support is provided, comprising a single-piece plastic element extending from a front cross member to a rear cross member of said plastic element in a longitudinal direction X of the seat and extending from a first side member to a second side member, in a transverse direction Y of said seat.
and wherein the front cross member, the rear cross member, the first side member and the second side member extending end-to-end to each other at the periphery of said plastic element,
and wherein said plastic element comprises an intermediate portion, extending in the transverse direction Y, connecting the first spar to the second spar, said intermediate portion arranged in an intermediate position between the front cross member and the rear cross member in the longitudinal direction,
and wherein said plastic element comprises a flexible suspension portion extending in a manner:
- preferably continuously in the longitudinal direction from the intermediate portion to the rear crosspiece of said plastic element by connecting said intermediate portion to the rear crosspiece,
- discontinuous in the transverse direction between the first spar and the second spar, said suspension portion separated along the length of the suspension portion, on the one hand, by a first lateral opening arranged between the first spar and said suspension portion, and on the other hand, by a second lateral opening arranged between the suspension portion and the second spar, said first lateral opening and the second lateral opening separating said suspension portion from the first spar and the second spar.

The features set out in the following paragraphs may, optionally, be implemented, independently of each other or in combination with each other:

According to one embodiment, the width of the suspension portion in the transverse direction, delimited between the first opening and the second opening, is less than 60% of the width of said plastic element between the first spar and the second spar in said transverse direction, for example between 25% and 50% of the width of said plastic element.

According to one embodiment, the suspension portion comprises recesses, blind or passing through, along a thickness of said suspension portion, said recesses distributed along a dimension of said suspension portion along the longitudinal direction, and/or along a dimension of said suspension portion along the transverse direction.

According to one embodiment, the area of said trim support delimited, along the longitudinal direction X, on the one hand, between the front cross member and the intermediate portion, and on the other hand, between the first side member and the second side member along the transverse direction, is hollowed out, preferably for the most part, the hollowed out portion delimiting on the one hand said front cross member, and a rear cross member forming said intermediate portion. The trim support may comprise at least one bridge of material, extending along the longitudinal direction X, connecting the intermediate cross member to said front cross member, locally between the front cross member and the intermediate cross member.

According to one embodiment, the trim support may comprise all or part of the following features:
- the surface void rate of said lining support is between 10% and 80%.
- the surface void rate of the suspension portion is between 10% and 80%,
- a mass of said plastic element less than 1.5 kg

According to one embodiment, said trim support can be configured to be fixed to a seat structure having a seat structure, typically metallic, comprising two lateral flanges braced by a front, transverse crosspiece and a rear, transverse tube,
and wherein said plastic element comprises a mechanical interface system having:
- a rear mechanical interface, materialized on the rear cross member, comprising a first housing, open, configured to house the rear tube in a pivotable manner around the rear tube,
- a front mechanical interface, on a front part of said support comprising a second housing, open, configured to house the front cross member in a mechanically lockable manner by a front mechanical interface locking system,
and wherein said mechanical interface system is configured to allow attachment of the trim support by the following steps:
/A/ aligning the rear mechanical interface with the rear tube and inserting the rear tube into the first housing, and
/B/ pivoting of the trim support around the rear tube then fitted into the first housing of the rear mechanical interface until the front cross member is inserted into the second housing of the front mechanical interface, and mechanical locking of the front cross member in the second housing by said locking system of the front mechanical interface.

According to one embodiment, the upholstery support can also be configured to be fixed to a seat structure having a seat structure, typically metallic, comprising two lateral flanges spaced by a front tube and a rear tube, and in which the upholstery support comprises said plastic element, as well as a removable accessory of the mechanical interface system comprising:
- a fixing portion fixed in the second housing of said plastic element,
- a coupling portion comprising a third housing complementary to the front tube, and in which said mechanical interface system is configured to allow the attachment of the trim support by the following steps:
/A/ aligning the rear mechanical interface with the rear tube and inserting the rear tube into the first housing, and
/B2/ pivoting of the trim support around the rear tube then fitted into the first housing of the rear mechanical interface until the front tube is inserted into the third housing of the accessory coupled to the front mechanical interface, and mechanical locking of the front tube in the third housing by a locking system, for example elastic.

According to one embodiment, said locking system of the front mechanical interface is elastically deformable, configured to allow elastic locking so that the locking of the front cross member in the second housing according to a first possibility, or the locking of the front tube in the third housing according to a second possibility, is obtained, at the end of the stroke during the pivoting carried out in step /B/ of the modular cushion around the rear tube, by elastic deformation of the locking system; in particular, said locking system may comprise the second housing forming a lower cavity which is delimited, in the longitudinal direction between a lower wall of the front cross member and a lower wall of the intermediate portion, in particular of the intermediate cross member and in the transverse direction between the first spar and the second spar, and an elastically deformable hook configured to hook the front cross member and/or

According to one embodiment, the first housing, in particular U-shaped, opens towards the rear of the trim support in a rear direction oriented from the front cross member towards the rear cross member, the first U-shaped housing having an upper wall and a lower wall, said upper and lower walls, opposite, as well as a bottom wall, said U-shaped housing being configured so as to ensure stable support of the rear tube against the bottom wall when the support exerts a force on the rear tube directed in the rear direction, the rear tube then blocked in a direction perpendicular to the support between the upper wall and the lower wall.

According to one embodiment, the upholstery support is configured to be fixed to a seat structure having a typically metallic seat structure comprising two side plates spaced by a front tube and a rear tube, and in which said plastic element comprising a mechanical interface system having:
- a rear mechanical interface, materialized on the rear cross member, comprising a first housing, open, configured to house the rear tube in a mechanically lockable manner by a locking system, in particular of the rear mechanical interface
- a front mechanical interface, on a front portion of said support comprising a second, open housing, configured to house the front tube in a pivotable manner around said front tube,
and wherein said mechanical interface system is configured to allow attachment of the trim support by the following steps:
/A2/ aligning the front mechanical interface with the front tube and inserting the front tube into the second housing, and
/B2/ pivoting of the trim support around the front tube then fitted into the second housing of the front mechanical interface until the rear tube is inserted into the first housing of the front mechanical interface and mechanical locking of the rear tube in the first housing by said locking system.

The present disclosure also relates to a seat assembly comprising a modular seat cushion and a seat structure having, according to a first possibility, a seat structure comprising two lateral flanges braced by a front, transverse crosspiece and a rear, transverse tube, or the seat structure having, according to a second possibility, a seat structure comprising two lateral flanges braced by a rear tube and a front tube.
and wherein, said modular seat cushion comprising, in the assembled state:
- a trim support according to the present disclosure,
- padding resting on an upper surface of the upholstery support
- a covering covering the padding
and wherein the upholstery support is secured to the seating structure preferably in a position in which:
- the front cross member and the rear cross member of said plastic element are supported, respectively, on the front cross member and on the rear tube of the seat structure according to the first possibility or else supported respectively on the front tube and the rear tube according to the second possibility
- the first spar and the second spar of said plastic element rest respectively on the two side plates.

Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the attached drawings, in which:

Fig. 1

is a perspective view of a trim support according to an embodiment of the present disclosure, comprising a front cross member and a rear cross member, as well as a first spar and a second spar, integral with each other on the periphery of the support, the support notably comprising a flexible suspension portion, extending longitudinally, between an intermediate portion and the rear cross member by connecting them, the suspension portion separated, on the one hand, from the first spar by a first lateral opening, and on the other hand, from the second spar by a second lateral opening.

Fig. 2

is a top view of the .

Fig. 3

is a bottom view of the .

Fig. 4

is a sectional view of the passing through a longitudinal vertical plane, more particularly illustrating a rear mechanical interface comprising a first housing, and a front mechanical interface comprising a second housing,

Fig. 5

is a view of a seating assembly that includes a modular seat cushion, and a seat structure in a disassembled state, the modular seat cushion including a support according to the , padding and a cover (or headdress), and according to an exploded view of the modular seat cushion.

Fig. 5b

is a schematic view of the assembly process of the modular seat cushion on the seat structure with:
- aligning the rear mechanical interface with the rear tube and inserting the rear tube into the first housing,
- pivoting of the modular cushion around the rear tube then fitted into the first housing of the rear mechanical interface until the front cross member is inserted into the second housing of the front mechanical interface and locked by a locking system of the front mechanical interface, in particular an elastic lock.

Fig. 6

is a perspective view of the plastic trim support assembled to the typically metal seat structure.

Fig. 7

is a sectional view, along a vertical plane, of the elastic assembly between the trim support and the seat structure.

Fig. 8

is a sectional view of the support of the associated with an accessory which is fixed in the second housing of the front mechanical interface to allow the fixing of the trim support to a seat structure comprising a front tube, without a front support cross member.

Fig. 9

is a view of a modular seat cushion according to a second aspect, in a disassembled state on the left and in an assembled state on the right, comprising a filling support, padding and a covering.

Fig. 10

is a view of an assembly kinematics relating to the modular cushion according to the second aspect illustrated in the , the kinematics comprising the placing of the front mechanical interface opposite the front tube, and a pivoting of the trim support around the front tube, then fitted into the second housing of the front mechanical interface, until an insertion of the rear tube into the first housing of the front mechanical interface, and mechanical locking of the rear tube in the first housing by said locking system in particular of the rear mechanical interface.

The present disclosure relates, according to a first aspect , to a seat upholstery support S, comprising (or typically consisting of) a single-piece plastic element 1 extending:
- from a front crosspiece 10 to a rear crosspiece 11 of said plastic element in a longitudinal direction X of the seat and,
- from a first spar 12 to a second spar 12, following a transverse direction Y of said seat.

Said plastic element 1 is typically obtained by molding techniques, typically injection molding.

The front cross member 10, the rear cross member 11 are substantially parallel in the transverse direction Y, on the one hand, and the first side member 12 and the second side member 13 are substantially parallel in the longitudinal direction X.

The front and rear cross members 10, 11 and the first and second side members 12, 13 extend end-to-end to each other on the periphery of said plastic element 1, forming a support frame.

The support frame can be configured to come to bear on the seat structure 2 of a vehicle seat, typically by bearing the side members 12, 13 of said plastic element on flanges 20 of the seat structure, and by bearings of the front cross member 10 and the rear cross member 11, on a front cross member 21 (or on a front tube 23) and on a rear tube 22 extending parallel to each other by connecting the two flanges 20.

Said plastic element 1 comprises an intermediate portion 14, extending in the transverse direction Y, the intermediate portion 14 connecting the first spar 12 to the second spar 13, said intermediate portion 14 arranged in an intermediate position between the front cross member 10 and the rear cross member 11 in the longitudinal direction X.

The intermediate position typically begins at a distance L14 from the front cross member 10 on the first half of the support 1 in the longitudinal direction X, in particular at a distance L14 between 1/6 and 1/3 from the front edge of the front cross member 10, for example at approximately ¼ of the distance from the front cross member 10

According to the present disclosure, said plastic element comprises a flexible suspension portion 15 extending continuously in the longitudinal direction X from the intermediate portion 14 to the rear cross member 11 of said plastic element by connecting said intermediate portion 14 to the rear cross member 11.

The suspension portion preferably extends discontinuously in the transverse direction Y between the first spar 12 and the second spar 1, said suspension portion 15 being separated, on the one hand, by a first lateral opening O1 arranged between the first spar 12 and said suspension portion 15, and on the other hand, by a second lateral opening O2 arranged between the suspension portion 15 and the second spar 13.

Said first lateral opening O1 and the second lateral opening O2 separate said suspension portion 15 from the first spar 12 and from the second spar 13 over the length L15 of the suspension portion 15, preferably continuously over the entire length L15 (example illustrated) or possibly discontinuously over the length L15 due to local interruption(s) of the first opening O1 and the second opening O2 over the length (according to an example not illustrated).

The suspension portion forms a flexible plastic blade which extends over the length L15 in the longitudinal direction X between the openings O1, O2, and in width l15 in the transverse direction Y from the first opening O1 to the second opening O2.

The suspension portion 15 has the function of receiving the buttocks of the seat occupant while allowing flexibility of the suspension portion under load, in the vertical direction Z.

The maximum flexibility in Z can be of the order of 30 mm, typically between 0.5 cm and 3 cm, for example between 1 cm and 3 cm for an average 75 kg mannequin.

The trim support 15 may advantageously be devoid of metal suspension, and the suspension being obtained solely by said plastic element 1, in one piece.

The width l15 of the suspension portion 15 in the transverse direction Y, delimited between the first opening O1 and the second opening O2 may be less than 60% of the width l1 of said plastic element between the first spar 12 and the second spar 13 in said transverse direction, for example between 25% and 50% of the width l1 of said plastic element. The suspension portion 15 typically extends over a median portion of said support in the transverse direction Y, and only partially over the width of the trim support. Such a dimensioning increases the flexibility under vertical stress of the suspension portion 15. The suspension portion extends over a rear portion of said support, near the rear crossmember 11, relatively to the front crossmember 10.

The first opening O1 and the second opening O2 thus have the function of conferring increased flexibility to the suspension portion 15, and also contribute to an overall objective of reducing material, and therefore the weight of said plastic trim support.

The flexible blade of the suspension portion can extend in length L15, for example along a dimension between 25% and 50% of the dimension of the support S along the longitudinal direction.

According to one embodiment, the flexible blade has all or part of the following characteristics:
- a length L15 between 200cm and 300cm, for example 270cm,
- a width l15 between 180cm and 250cm, for example 220cm,
- a thickness e15 between 1mm and 4mm, for example 2.5mm.

Generally speaking, and as illustrated for information purposes according to the view of the , the S trim support may have all or part of the following characteristics:
- the upper face of the suspension portion can form a bowl, in the longitudinal direction X,
- the suspension portion 15 can be arranged on the trim support, below the front portion of the support 1, the front portion comprising the front crossmember 10 and the intermediate portion 14.

The support profile of the trim support may be rising in the longitudinal direction X, from the rear cross member 11 to the front part of said support. Such a support profile prevents the phenomenon of the seat occupant being submerged, i.e. passing under the seat belt, in the event of a frontal impact.

The suspension portion 15 can extend below the level of the first spar 12 and the second spar 13.

In general, and as illustrated by way of example in the figures, the suspension portion 15 may comprise recesses 150 (blind or through) along a thickness of said suspension portion. The recesses 150 are distributed along a length dimension of said suspension portion 15, namely along the longitudinal direction X, and in particular over its entire length L15 or beyond, and/or along a dimension of said suspension portion 15 along the transverse direction Y and in particular over its entire width l15. The surface void rate of the suspension portion 15 is between 10% and 80%, in particular in the presence of through recesses, and for example greater than 20%, or even greater than 30%, or even greater than 40%, or even greater than 50%.

The recesses help to provide flexibility to the suspension portion in the vertical direction Z, and contribute to reducing the mass of said trim support 1.

According to one embodiment, the zone Z of said trim support delimited, in the longitudinal direction X, on the one hand, between the front cross member 10 and the intermediate portion 14, and on the other hand, between the first side member 12 and the second side member 13 in the transverse direction Y, can advantageously be hollowed out.

The hollowed-out portion, consisting of a third opening O3, and a fourth opening O4 according to an illustrated embodiment, physically delimits, on the one hand, said front crosspiece 10, and, on the other hand, a rear crosspiece 140 forming the intermediate portion 14. The hollowed-out portion can extend over a major part of the surface of the support between said front crosspiece 10 and the intermediate crosspiece 140.

Such an embodiment finds a particular application when the front portion of the trim support 1 delimited between the front crosspiece 10 and the intermediate crosspiece 14 of said support is supported by a front crosspiece 21, typically metallic of the seat structure, and as illustrated in and in particular by a support wall of the front crosspiece 21 cooperating to support the thighs of the occupant of the seat, by covering the hollowed-out part, in particular the openings O3 and O4, in order to support the thighs in the hollowed-out parts.

According to such an embodiment, at least one material bridge 141 can extend in the longitudinal direction X, connecting the intermediate crosspiece 140 to said front crosspiece 10, locally between the front crosspiece and the intermediate crosspiece, for example between median portions of the crosspieces 10, 14.

According to another embodiment (not illustrated), the front portion of the trim support can be reinforced, and preferably solid between the front cross member and the intermediate portion, in particular without physical distinction of the intermediate cross member. Such an embodiment finds a particular application when said support is intended to cooperate with a seat structure without a front cross member, with a thigh support function. In such a case, the trim support can be configured to come to rest on a front tube 23, and only locally via the front mechanical interface. The front portion of the support, not hollowed out, makes it possible to take up the load of the thighs over its width.

In general, the trim support and the plastic element have the first opening O1, the second opening O2, or even the recesses 150 on the suspension portion or even the recessed portion and the front zone Z of the support, comprising in particular a third opening O3 and a fourth opening O4.

The lining support can thus have a surface void rate (along the XY plane) of said support greater than 10%, between 10% and 80%, for example greater than 20%, or even 30%, or even 40%, or even 50%, or even 60%.

The plastic element 1 may have a reduced mass, in particular less than 2 kg, or even less than 1.5 kg, for example between 1.5 kg and 0.4 kg. Generally speaking, such a reduction in the mass of the trim support S makes it possible to save material.

According to one embodiment, the trim support, in particular said plastic element 1, is configured to be fixed to a seat structure having a seat structure 2 comprising two lateral flanges 20 spaced by a transverse front crosspiece 2 and a transverse rear tube 22.

For this purpose, said plastic element may comprise a mechanical interface system:
- a rear mechanical interface 16, materialized on the rear cross member 11, comprising a first housing LG1, open, configured to house the rear tube in a pivotable manner around the rear tube 22,
- a front mechanical interface 17, on a front part of said support comprising a second housing LG2, open, configured to house the front cross member 21 in a mechanically lockable manner by a front mechanical interface locking system.

Advantageously, and according to one embodiment, said mechanical interface system can be configured to allow the fixing of the support in particular, of the modular seat cushion defined below, by the following steps:
/A/ placing the rear mechanical interface opposite the rear tube 22 and inserting the rear tube into the first housing LG1, and
/B/ pivoting of the trim support around the rear tube then fitted into the first housing LG1 of the rear mechanical interface 16 until the front cross member 21 is inserted into the second housing LG2 of the front mechanical interface 17, and mechanical locking of the front cross member 21 in the second housing LG2 by said locking system of the front mechanical interface 17.

Such a kinematics of mounting the trim support, and in particular said plastic element 1 on the seat structure is illustrated in .

According to one embodiment, the first U-shaped housing LG1 opens towards the rear of the support 1 in a rear direction oriented from the front cross member 11 towards the rear cross member 10, the first U-shaped housing LG1 having an upper wall and a lower wall as well as a bottom wall, the upper and lower walls being opposite.

Said first U-shaped housing LG1 is configured so as to ensure stable support of the rear tube 22 against the bottom wall when the trim support exerts a force on the rear tube 22 directed in the rear direction, the rear tube 22 then blocked in a direction perpendicular to the support between the upper wall and the lower wall of the first housing LG1.

According to one embodiment, the second housing LG2 opens out below said plastic element 1. The second housing LG2 can be materialized on the front portion of said plastic element by a lower cavity, delimited:
- along the longitudinal direction X between the front cross member 10 and the intermediate cross member 14, and
- along the transverse direction Y between the first spar 12 and the second spar 13.

The front crosspiece 41 and the second housing LG2 are preferably of complementary shapes, with the interlocking clearance. An upper support surface of the front crosspiece 41, substantially flat, participates in supporting the front portion of the trim support, in particular said plastic element 1 on the front part, and in particular on the surface delimited between the front crosspiece 11 and the intermediate crosspiece 14 configured for supporting the thighs of the occupant of the seat, namely the surface of said plastic element which can be perforated, with in particular the third opening O3 and the fourth opening O4.

According to one embodiment, said locking system of the front mechanical interface 17 is elastically deformable, configured to allow elastic locking so that the locking of the front cross member 21 in the second housing LG2 is obtained, at the end of the stroke during the pivoting carried out in step /B/ of the trim support, in particular of the modular cushion, around the rear tube 22, by elastic deformation of the locking system.

In particular when said locking system comprises the lower cavity delimited, in the longitudinal direction X between a lower wall of the front crossmember 11 and a lower wall of the intermediate portion 14, and in the transverse direction Y between the first spar 12 and the second spar 13, the locking system may comprise an elastically deformable hook 170 for example projecting from the intermediate crossmember configured to hook the front crossmember 21.

When pivoting at /B/, the hook 170 is elastically deformed before returning elastically, at the end of the pivoting stroke, to hook the front crosspiece 21 then housed in the second housing LG2, ensuring the locking of said plastic element 12 on the seat structure, and as illustrated for information purposes in FIG. .

According to one embodiment (illustrated in particular in the ), said trim support 1 can be configured to be fixed to a seat structure having a typically metallic seat structure 2 (or even made of another material, in particular composite) comprising two lateral flanges 20 spaced by a front tube 23 and a rear tube 22, and in which the trim support S comprises said plastic element 1, as well as a removable accessory 100 of the mechanical interface system.

The accessory 100, forming a removable part of said mechanical interface system, may comprise:
- a fixing portion 101 configured fixed in the second housing LG2 of said plastic element 1,
- a coupling portion 102 comprising a third housing LG3 complementary to the front tube 23.

Said mechanical interface system can be configured to allow the attachment of the upholstery support, in particular of the modular seat cushion by the following steps:
- /A/ placing the rear mechanical interface opposite the rear tube 22 and inserting the rear tube 23 into the first housing LG1, and
- /B1/ pivoting of the trim support around the rear tube 22 then fitted into the first housing LG1 of the rear mechanical interface 16 until the front tube 23 is inserted into the third housing LG3 of the accessory coupled to the front mechanical interface 17, and mechanical locking of the front tube 23 in the third housing LG3 by a locking system, for example elastic.

A trim support S, with its accessory 100 can thus advantageously respond to different designs of seat structure 2, namely those (ie figures 5a, 6) comprising a front crosspiece 21 when the accessory is not used, and those comprising a front tube 23 (ie ) but without a front cross member 21 with a support function when the accessory 100 is coupled to the trim support S.

According to one embodiment, said locking system of the front mechanical interface is elastically deformable, configured to allow elastic locking so that the locking of the third housing LG3 is obtained, at the end of the stroke during the pivoting carried out in step /B/ of the modular cushion around the rear tube 22, by elastic deformation of the locking system, in particular elastically deformable of the third housing LG3 which can comprise a groove entry, of a dimension smaller than the section of the front tube and a central portion housing the rear tube 22.

According to an embodiment illustrated as a non-limiting example in FIGS. 9 and 10, the upholstery support being configured to be fixed to a seat structure having a seat structure 2, typically metallic (or even made of another material) comprising two lateral flanges 20 spaced by a front tube 23 and a rear tube 22, said plastic element 1 comprising a mechanical interface system having:
- a rear mechanical interface 16, materialized on the rear cross member 11, comprising a first housing LG1, open, configured to house the rear tube 22 in a mechanically lockable manner by a locking system, in particular of the rear mechanical interface
- a front mechanical interface 17, on a front part of said support comprising a second housing LG2, open, configured to house the front tube 23 in a pivotable manner around said front tube 23.

Said mechanical interface system is configured to allow the attachment of the support, in particular of the modular seat cushion, by the following steps, and as illustrated by way of non-limiting example in the :
/A2/ placing the front mechanical interface 17 next to the front tube 23 and inserting the front tube into the second housing LG2, and
/B2/ pivoting of the trim support around the front tube 23, then fitted into the second housing LG2 of the front mechanical interface 17 until the rear tube 22 is inserted into the first housing LG1 of the front mechanical interface and mechanical locking of the rear tube 22 in the first housing LG1 by said locking system, in particular of the rear mechanical interface 16.

According to one embodiment, and as illustrated in the , the second housing LG2, typically secured near the front crossmember, opens towards the front of the trim support S, namely in the direction following the longitudinal direction X going from the rear crossmember 11 to the front crossmember 10. The first housing LG1 and the second housing LG2 can be U-shaped housings.

The first housing LG1, opens towards the bottom, typically following the vertical direction Z.

Generally, the first housing LG1 comprises a first insertion direction D1 for the rear tube 22 and the second housing LG2 comprises a second insertion direction D2 for the front tube 23, the first insertion direction D1 and the second insertion direction D2 being inclined relative to each other by an angle of between 45° and 90°.

In general, said locking system may belong to the rear mechanical interface and possibly be an elastically deformable locking system, configured to allow elastic locking so that the locking of the rear tube 22 in the first housing LG1 is obtained, at the end of the stroke during the pivoting carried out in step /B/ of the modular cushion around the front tube 23, by elastic deformation of the locking system of the front mechanical interface 16.

According to another locking possibility, the locking of the rear tube 22 in the first housing LG1 is obtained by placing a backrest element, in particular a modular backrest cushion on a backrest structure. Once said backrest element is fixed to the backrest structure, it forms a stop preventing the rear tube 22 from exiting the first housing LG1, by pivoting around the front tube 23.

The present disclosure also relates to a seat assembly comprising a modular seat cushion and a seat structure having, according to a first possibility, a seat structure 2, typically metallic, comprising two lateral flanges 20 spaced by a transverse front crosspiece 21 and a transverse rear tube 22, or even a seat structure comprising, according to a second possibility, a seat structure 2 comprising two lateral flanges 20 spaced by a rear tube 22 and a front tube 23.

The CM modular seat cushion comprising, in the assembled state:
- a trim support 1 according to the present disclosure,
- a MA padding resting on an upper surface of the plastic element 1 of the trim support
- a CF upholstery covering the padding.

The CM seat module cushion may typically be pre-assembled, particularly at a manufacturing site separate from the final assembly site of the seat module cushion onto the seat structure 2 of the seat.

The lower padded part may be shaped to complement the shape of the trim support. The trim covering covers the padding and may be fixed by its edges to the periphery of said support element. For example, said plastic element 1 may have on the periphery, in particular along a peripheral skirt JP materialized by the front cross member 10, on the one hand, part, and the first side member 12 and the second side member 13, on the other hand. The skirt extends towards the bottom of an upper wall, typically substantially horizontal

The Rac attachment groove can run along the periphery of the JP skirt, for example at a lower part of the JP skirt. The Rac attachment groove can be provided with elastic clipping parts Fx, obtained during molding. The CF trim covering can be provided with an attachment rib configured to elastically fit into the attachment groove, locked by the elastic clipping parts.

The suspension portion 15 of the upholstery support, providing flexibility in the vertical direction Z, can typically allow the amount of padding to be reduced, particularly the thickness of the padding, at least in the suspension area, without sacrificing the comfort of the seat occupant. Reducing the amount of padding can be particularly advantageous from an environmental point of view, particularly when the padding is, by way of non-limiting example, a polyurethane foam, which can be difficult to recycle.

Generally, the trim support S can be fixed to the seat structure 2 in a position in which:
- the front cross member 10 and the rear cross member 11 of said plastic element are supported, respectively, on the front cross member 21 and on the rear tube 22 of the seat structure, according to the first possibility, or else supported respectively on the front tube 23 and the rear tube 22 according to the second possibility.
- the first spar 12 and the second spar 13 of said plastic element bear respectively on the two lateral flanges 20.

The JP skirt which runs continuously along the front cross member and the first and second side members, typically partially overlaps vertically, respectively the front cross member and the two flanges.

The present disclosure further relates to a method of obtaining a seat assembly in the assembled state comprising the following steps:
- supply of a modular seat cushion CM comprising, in the assembled state, at least one upholstery support having said mechanical interface system, padding MA resting on said plastic element 1 and a covering CF,
- provision of a seat structure, in the assembled state, comprising a seat structure 2 and a backrest structure, the seat structure comprising two lateral flanges 20 braced by a transverse front crosspiece 21 and a transverse rear tube 22 according to the first possibility, or a seat structure 2 comprising two lateral flanges 20 braced by a rear tube 22 and a front tube 23 according to the second possibility
- assembly of the modular cushion to said seat structure in particular by implementing the following steps:
/A/ placing the rear mechanical interface 16 next to the rear tube and inserting the rear tube 21 into the first housing LG1 and
/B/ pivoting of the modular cushion around the rear tube 22, then fitted into the first housing LG1 of the rear mechanical interface until the front cross member 21 is inserted into the second housing LG2 of the front mechanical interface and locked by the locking system of the front mechanical interface 17 according to the first possibility or alternatively,
/B1/ pivoting of the trim support around the rear tube 22 then fitted into the first housing LG1 of the rear mechanical interface 16 until the front tube 23 is inserted into the third housing LG3 of the accessory coupled to the front mechanical interface 17, and mechanical locking of the front tube 23 in the third housing LG3 by a locking system, for example elastic, according to the second possibility.

The present disclosure further relates to a method of obtaining a seat assembly in the assembled state comprising the following steps:
- supply of a modular seat cushion CM comprising, in the assembled state, at least one upholstery support having said mechanical interface system, padding MA resting on said plastic element 1 and a covering CF,
- supply of a seat structure, in the assembled state, comprising a structure 2 comprising two side plates 20 spaced by a rear tube 22 and a front tube 23 according to the second possibility
- assembly of the modular cushion to said seat structure by implementing the following steps:
/A2/ placing the front mechanical interface 17 next to the front tube 23 and inserting the front tube into the second housing LG2, and
/B2/ pivoting of the trim support around the front tube 23 then fitted into the second housing LG2 of the front mechanical interface 17 until the rear tube 22 is inserted into the first housing LG1 of the front mechanical interface and mechanical locking of the rear tube 2222 in the first housing LG1 by said locking system, in particular of the rear mechanical interface 16.

Generally speaking, during maintenance, it is possible to easily remove the modular seat cushion CM by a kinematics inverse to the sequence of steps /A/ and /B/ or inverse to the sequence of steps /A/, /B1/ when in the presence of the accessory 100 coupled to the support S, or even inverse to the sequence of steps /A2/ and /B2/.

Preferably, the disassembly sequence can typically be implemented in a vehicle, without requiring the disassembly of the seat structure from the vehicle floor, greatly facilitating maintenance operations.

In general, the present disclosure also relates, according to a second aspect totally independent of the first aspect, to a modular seat cushion CM, configured to be fixed to a seat structure2 having a seat structure comprising two lateral flanges 20 spaced by a front tube 23, transverse, and a rear tube 22, transverse,
said modular seat cushion comprising in the assembled state:
- a support S forming a base comprising a mechanical interface system for fixing to the seat structure,
- a MAT padding resting on an upper surface of the support
- a CF upholstery covering the padding,
and wherein said mechanical interface system comprises:
- a rear mechanical interface 16, on a rear portion of the support S, comprising a first housing LG1, open, configured to house the rear tube 22 in a mechanically lockable manner by a locking system, in particular of the rear mechanical interface
- a front mechanical interface 17, on a front part of said support comprising a second housing LG2, open, configured to house the front tube 23 in a pivotable manner around said front tube 23.

Said mechanical interface system is configured to allow the attachment of the modular seat cushion by the following steps, and as illustrated by way of non-limiting example in the :
/A2/ placing the front mechanical interface 17 next to the front tube 23 and inserting the front tube into the second housing LG2, and
/B2/ pivoting of the trim support around the front tube 23 then fitted into the second housing LG2 of the front mechanical interface 17 until the rear tube 22 is inserted into the first housing LG1 of the front mechanical interface and mechanical locking of the rear tube 22 in the first housing LG1 by said locking system.

According to one embodiment, and as illustrated in the , the second housing LG2, typically integral near the front crossmember 10, opens towards the front of the trim support 1, namely in the direction following the longitudinal direction X going from a rear crossmember 11 of the support to a front crossmember 10 of said support. The first housing LG1 and the second housing LG2 may be U-shaped housings.

The first housing LG1, opens towards the bottom, typically following the vertical direction Z.

Generally, the first housing LG1 comprises a first insertion direction D1 for the rear tube 22 and the second housing LG2 comprises a second insertion direction D2 for the front tube 23, the first insertion direction D1 and the second insertion direction D2 being inclined relative to each other by an angle of between 45° and 90°.

In general, said locking system of the rear mechanical interface 16 may be elastically deformable, configured to allow elastic locking so that the locking of the rear tube 22 in the first housing LG1 is obtained, at the end of the stroke during the pivoting carried out in step /B/ of the modular cushion around the front tube 23, by elastic deformation of the locking system of the rear mechanical interface 16. For this purpose, the first housing LG1 may be elastically deformable and comprise a groove entry of a dimension smaller than the section of the rear tube 22, and a central portion housing the rear tube in the locking position adjusted to the section of the rear tube 22.

According to another locking possibility, the locking of the rear tube 22 in the first housing LG1 is obtained by placing a backrest element, in particular a modular backrest cushion on a backrest structure. Once said backrest element is fixed to the backrest structure, it forms a stop preventing the rear tube 22 from exiting the first housing LG1, by pivoting around the front tube 23.

The trim support S may be a plastic element 1 typically obtained by injection molding. The front and rear mechanical interfaces 16, 17 are preferably obtained by the material coming from the trim support, typically obtained during the molding of said trim support 1. In other words, the front and rear mechanical interface and the first housing LG1 and the second housing LG2 form a plastic element in one piece with the body of the trim support S.

Generally speaking, said single-piece plastic element 1 can extend
- from a front crosspiece 10 to a rear crosspiece 11 of said plastic element in a longitudinal direction X of the seat and,
- from a first spar 12 to a second spar 12, following a transverse direction Y of said seat.

Said plastic element 1 is typically obtained by molding techniques, typically injection molding.

The front cross member 10, the rear cross member 11 are substantially parallel in the transverse direction Y, on the one hand, and the first side member 12 and the second side member 13 are substantially parallel in the longitudinal direction X.

The front and rear cross members 10, 11 and the first and second side members 12, 13 extend end-to-end to each other on the periphery of said plastic element 1, forming a support frame.

The support frame is configured to come to bear on the seat structure 2 of a vehicle seat, typically by bearing the side members 12, 13 of said plastic element on flanges 20 of the seat structure, and by bearing the front cross member and the rear cross member, on a cross member on the front tube 23 and on the rear tube 22 extending parallel to each other by connecting the two flanges 20.

The present disclosure relates, still according to this second aspect, to a seat assembly comprising a modular seat cushion and a seat structure 2 comprising two side plates 20 spaced by a rear tube 22 and a front tube 2 in which,
said CM modular seat cushion comprising, in the assembled state:
- a S trim support,
- a MA padding resting on an upper surface of the upholstery support
- a CF upholstery covering the padding
and wherein the trim support S is fixed to the seat structure2 in a position in which:
- the front cross member 10 and the rear cross member 11 of said plastic element are supported, respectively, on the front tube 23 and the rear tube 22 via said front mechanical interface 16 and said rear mechanical interface 17
- the first spar 12 and the second spar 13 of said plastic element bear respectively on the two lateral flanges 20.

The Applicant reserves the right to file a divisional application on the disclosure which is the subject of this second aspect illustrated as an example in Figures 9 and 10.

Claims (11)

Seat upholstery support (S), comprising a single-piece plastic element (1) extending from a front cross member (10) to a rear cross member (11) of said plastic element in a longitudinal direction X of the seat and extending from a first longitudinal member (12) to a second longitudinal member (13), in a transverse direction Y of said seat.
and wherein the front cross member (10), the rear cross member (11), the first side member (12) and the second side member (13) extend end-to-end to each other at the periphery of said plastic element,
and wherein said plastic element (1) comprises an intermediate portion (14), extending in the transverse direction Y, connecting the first spar (12) to the second spar (13), said intermediate portion (14) arranged in an intermediate position between the front cross member (10) and the rear cross member (11) in the longitudinal direction (X),
and wherein said plastic element (1) comprises a flexible suspension portion (15) extending in a manner:
- continues in the longitudinal direction (X) from the intermediate portion (14) to the rear crosspiece (11) of said plastic element by connecting said intermediate portion (14) to the rear crosspiece (11),
- discontinuous in the transverse direction (Y) between the first spar (12) and the second spar (13), said suspension portion (15) separated along the length (L15) of the suspension portion (15), on the one hand, by a first lateral opening (O1) arranged between the first spar (12) and said suspension portion (15), and on the other hand, by a second lateral opening (O2) arranged between the suspension portion (15) and the second spar (13), said first lateral opening (O1) and the second lateral opening (O2) separating said suspension portion (15) from the first spar (12) and the second spar (13). Seat upholstery support according to claim 1, in which the width (l15) of the suspension portion (15) in the transverse direction, delimited between the first opening (O1) and the second opening (O2) is less than 60% of the width (l1) of said plastic element between the first side member (12) and the second side member (13) in said transverse direction, for example between 25% and 50% of the width (l1) of said plastic element. Seat upholstery support according to claim 1 or 2, in which the suspension portion (15) comprises recesses (150), blind or passing through along a thickness of said suspension portion, said recesses (150) distributed along a dimension of said suspension portion (15) along the longitudinal direction (X), and/or along a dimension of said suspension portion (15) along the transverse direction (Y). Seat upholstery support, according to one of claims 1 to 3, in which the zone (Z) of said upholstery support delimited, in the longitudinal direction X, on the one hand, between the front cross member (10) and the intermediate portion (14), and on the other hand, between the first side member (12) and the second side member (13) in the transverse direction (Y), is hollowed out, preferably for the most part, the hollowed out portion (O3, O4) delimiting on the one hand said front cross member (10), and a rear cross member (140) forming said intermediate portion (14). Seat upholstery support according to claim 4, having at least one material bridge (141), extending in the longitudinal direction X, connecting the intermediate crosspiece (140) to said front crosspiece (10), locally between the front crosspiece (10) and the intermediate crosspiece (140). Trim support according to one of claims 1 to 5, having all or part of the following characteristics:
- the surface void rate of said lining support (S) is between 10% and 80%.
- the surface void rate of the suspension portion (15) is between 10% and 80%,
- a lower mass of said plastic element (1) less than 1.5 kg Seat upholstery support according to one of claims 1 to 6, configured to be fixed to a seat structure having a seat structure (2), typically metallic, comprising two lateral flanges (20) braced by a front crosspiece (21), transverse, and a rear tube (22), transverse,
and wherein said plastic element (1) comprising a mechanical interface system:
- a rear mechanical interface (16), materialized on the rear cross member (11), comprising a first housing (LG1), open, configured to house the rear tube in a pivotable manner around the rear tube (22),
- a front mechanical interface (17), on a front part of said support comprising a second housing (LG2), open, configured to house the front cross member (21) in a mechanically lockable manner by a front mechanical interface locking system,
and wherein said mechanical interface system is configured to allow attachment of the trim support by the following steps:
/A/ aligning the rear mechanical interface with the rear tube (22) and inserting the rear tube into the first housing (LG1), and
/B/ pivoting of the trim support around the rear tube (22) then fitted into the first housing (LG1) of the rear mechanical interface (16) until the front cross member (21) is inserted into the second housing (LG2) of the front mechanical interface (17), and mechanical locking of the front cross member (21) in the second housing (LG2) by said locking system of the front mechanical interface (17). Trim support according to claim 7, configured to be fixed to a seat structure having a seat structure (2), typically metallic, comprising two lateral flanges (20) spaced by a front tube (23) and a rear tube (22), and in which the trim support (S) comprises said plastic element (1), as well as an accessory (100), removable, of the mechanical interface system comprising:
- a fixing portion (101) fixed in the second housing (LG2) of said plastic element (1),
- a coupling portion (102) comprising a third housing (LG3) complementary to the front tube (23), and in which said mechanical interface system is configured to allow the attachment of the trim support by the following steps:
/A/ placing the rear mechanical interface opposite the rear tube (22) and inserting the rear tube (23) into the first housing (LG1), and
/B1/ pivoting of the trim support around the rear tube (22) then fitted into the first housing (LG1) of the rear mechanical interface (16) until the front tube (23) is inserted into the third housing (LG3) of the accessory coupled to the front mechanical interface (17), and mechanical locking of the front tube (23) in the third housing (LG3) by a locking system, for example elastic. A trim support according to claim 7 or 8 having all or part of the following characteristics:
- said locking system of the front mechanical interface is elastically deformable, configured to allow elastic locking so that the locking of the front cross member (21) in the second housing (LG2) according to a first possibility, or the locking of the front tube (23) in the third housing (LG3) according to a second possibility, is obtained, at the end of the stroke during the pivoting carried out in step /B/ of the modular cushion around the rear tube (21), by elastic deformation of the locking system, in particular said locking system comprising the second housing (LG2) forming a lower cavity delimited, in the longitudinal direction (X) between a lower wall of the front cross member (11) and a lower wall of the intermediate portion (14) in particular of the intermediate cross member (140) and in the transverse direction (Y) between the first spar (12) and the second spar (13), and an elastically deformable hook (170) configured to hook the front cross member and/or
- the first U-shaped housing (LG1) opens towards the rear of the support (1) in a rear direction oriented from the front crosspiece (11) towards the rear crosspiece (10), the first U-shaped housing (LG1) having an upper wall and a lower wall, said upper and lower walls, opposite, as well as a bottom wall, said U-shaped housing being configured so as to ensure stable support of the rear tube (22) against the bottom wall when the support exerts a force on the rear tube directed in the rear direction, the rear tube (22) then blocked in a direction perpendicular to the support between the upper wall and the lower wall. Upholstery support according to one of claims 1 to 6, configured to be fixed to a seat structure having a seat structure (2), typically metallic, comprising two lateral flanges (20) spaced by a front tube (23) and a rear tube (22), and in which said plastic element (1) comprising a mechanical interface system having:
- a rear mechanical interface (16), materialized on the rear cross member (11), comprising a first housing (LG1), open, configured to house the rear tube in a mechanically lockable manner by a locking system in particular of the rear mechanical interface
- a front mechanical interface (17), on a front part of said support comprising a second housing (LG2), open, configured to house the front tube (23) in a pivotable manner around said front tube (23),
and wherein said mechanical interface system is configured to allow attachment of the trim support by the following steps:
/A2/ placing the front mechanical interface (17) next to the front tube (23) and inserting the front tube (23) into the second housing (LG2), and
/B2/ pivoting of the trim support around the front tube (23) then fitted into the second housing (LG2) of the front mechanical interface (17) until the rear tube (22) is inserted into the first housing (LG1) of the front mechanical interface and mechanical locking of the rear tube (22) in the first housing (LG1) by said locking system. Seat assembly comprising a modular seat cushion and a seat structure having, according to a first possibility, a seat structure (2) comprising two lateral flanges (20) braced by a transverse front crosspiece (21) and a transverse rear tube (22), or according to a second possibility a seat structure (2) comprising two lateral flanges (20) braced by a rear tube (22) and a front tube (23) in which,
said modular seat cushion (CM) comprising, in the assembled state:
- a trim support (S) according to one of claims 1 to 10,
- a padding (MA) resting on an upper surface of the upholstery support
- a covering covering (CF) covering the padding
and wherein the upholstery support (1) is secured to the seat structure (2) in a position in which:
- the front crosspiece (10) and the rear crosspiece (11) of said plastic element are supported, respectively, on the front crosspiece (21) and on the rear tube (22) of the seat structure according to the first possibility or else supported respectively on the front tube (23) and the rear tube (23) according to the second possibility
- the first spar (12) and the second spar (13) of said plastic element bear respectively on the two side plates (20).
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